Perennial weeds, such as morning glory, also known as field bindweed, have not been adequately controlled and millions of acres of fertile farm land are severely infected. Residual herbicides and persistant soil sterilants have been used through application to foliage, soil surfaces and shallow incorporation into soil. However, the application costs have been high and adequate control has not been achieved. Moreover, there are disadvantages, such as: residual chemicals remain in the soil; there are partial losses of one or more crops, due to toxic chemicals; there is the potential of chemical residue contamination in successive food crops; and there is the possibility of the unwanted movement of the toxic entity of chemicals to other areas by leaching and/or surface run-off in natural water. In general, the application of any residual chemical to soil or foliage has the inherent danger of polluting the environment through contamination of ground and surface water. As a result, restrictions have been placed on the current usage of many chemicals formerly used in gaining some control over morning glory, Canadian thistle and other perennial weeds. This invention therefore is directed to effectively controlling and often eliminating the growth of these perennial weeds, while avoiding the unwanted after effects and complying with the directives of government agencies.